Auto focus speed K5 vs K20d??

I originally had the Sigma 50-150mm but sold it when I bought the 50-135mm because the IQ just edged it on the Pentax and I thought I could put up with the focus speed. Have since sold the Pentax and bought another Sigma because I couldn't.

17-70mm is faster to focus than the 50-135mm .. infact the only lens slower is the 55mm where I find it quicker to leave it in the middle and run back or forward to focus.

Are you still happy with this decision or do you miss the DA* at all?

But the DA*50-135 doesn't hunt which i hear is a problem sometimes with the DA17-70.

But that wasn't the question was it, as usual you are just complicating things Stefan.

Mhuni has the 17-70mm and just wanted a comparison between the two with regard to AF speed.

I mainly use the 60-250mm so the 50-135mm was mostly unused, the Sigma was a cheap alternative which I can use if I need f2.8 (which is rare).

Do I miss the DA* ... yes, the build quality alone is worth the extra but that AF .... arghhh, drove me bonkers.

Would presume its faster on the K-5 though .. my other DA* lenses are.

And here i'm complicating things and not reading things well...

He didn't say specifically the AF speed, i know this is the big factor in this topic but the way Mhuni asked the question looks like he wanted a more general answer or not, with word like "behave"...

And you still wonder why people were having a dig at you all those months ago. ?

Stefan, the clue is in the words: "I was wondering about the AF comparisons"

G

And you know what i think
And what dig do you mean???

Well explain George.

From what i understand it's this.
Okay, so comparing the 17-70 & 50-135 AF behavior wise for an impression.

From that i concluded it's about all AF behaviors so how fast the AF is and if it locks on well and maybe other things that have to do with the AF.
If it's only about speed then why not use the word speed instead of behave...

Thanks for the feedback everyone.

Interesting to know that your preferred choice is the 60-250, Mike. I thought the AF was as bad, if not worse, than the 50-135 on this lens.

Had the change to test the DA*200, DA*300, DA*60-250, DA*55 and the Sigma 100-300 today and i've the DA*16-50 and the DA*50-135 myself.

the DA*55 was the slowest of them all, from what i could tell there was little difference between the DA*50-135 and the DA*60-250 on the K5.
the DA*200 and the DA*300 where actually pretty fast but the DA*16-50 is still one of the fastest SDM lenses. the Sigma 100-300 was blazing fast on the K5, the DA*60-250 was no match for it.
There was also the SIgma70-200 but didn't test that one, sorry!